/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

package ai.h2o.sparkling.ml.params

import java.util

import hex.KeyValue
import org.apache.spark.ml.param.Params

import collection.JavaConverters._

trait HasMonotoneConstraints extends Params {
  private val monotoneConstraints = new DictionaryParam(
    this,
    "monotoneConstraints",
    "A key must correspond to a feature name and value could be 1 or -1")

  setDefault(monotoneConstraints -> new util.HashMap[String, Double]())

  def getMonotoneConstraints(): Map[String, Double] = $(monotoneConstraints).asScala.toMap

  def setMonotoneConstraints(value: Map[String, Double]): this.type = set(monotoneConstraints, value.asJava)

  protected def getMonotoneConstraintsAsKeyValuePairs(): Array[KeyValue] = {
    val constraints = getMonotoneConstraints()
    if (constraints == null) {
      null
    } else {
      getMonotoneConstraints().map {
        case (key, value) => new KeyValue(key, value)
      }.toArray
    }
  }
}
